The extent to which immune responses to natural infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and immunization with vaccines protect against variants of concern (VOC) is of increasing importance. Accordingly, here we analyse antibodies and T cells of a recently vaccinated, UK cohort, alongside those recovering from natural infection in early 2020. We show that neutralization of the VOC compared to a reference isolate of the original circulating lineage, B, is reduced: more profoundly against B.1.351 than for B.1.1.7, and in responses to infection or a single dose of vaccine than to a second dose of vaccine. Importantly, high magnitude T cell responses are generated after two vaccine doses, with the majority of the T cell response directed against epitopes that are conserved between the prototype isolate B and the VOC. Vaccination is required to generate high potency immune responses to protect against these and other emergent variants.
Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
Medawar Laboratory Team, OPTIC (Oxford Protective T cell Immunology for COVID-19) Clinical Group, PITCH (Protective Immunity T cells in Health Care Worker) Study Group, C-MORE/PHOSP-C Group, T-Lymphocytes, Animals, Humans, Carrier Proteins, Antibodies, Monoclonal, Antibodies, Viral, Epitopes, Immunity, Antibodies, Neutralizing, COVID-19, Angiotensin-Converting Enzyme 2, SARS-CoV-2, COVID-19 Vaccines